World Trade Center
The original World Trade Center was a large complex of seven buildings in Lower Manhattan, New York City, United States. It featured the landmark Twin Towers, which opened on April 4, 1973 and were destroyed in 2001 during the September 11 attacks. At the time of their completion, the Twin Towers — the original 1 World Trade Center, at 1,368 feet; and 2 World Trade Center, at 1,362 feet — were the tallest buildings in the world. Other buildings in the complex included the Marriott World Trade Center (3 WTC), 4 WTC, 5 WTC, 6 WTC, and 7 WTC. The complex was located in New York City's Financial District and contained 13,400,000 square feet of office space. The core of the complex was built between 1975 and 1985, with a cost of $400 million (equivalent to $2.27 billion in 2011). The World Trade Center experienced a fire on February 13, 1975, a bombing on February 26, 1993, and a bank robbery on January 14, 1998. In 1998, the Port Authority decided to privatize the World Trade Center, leasing the buildings to a private company to manage, and awarded the lease to Silverstein Properties in July 2001. On the morning of September 11, 2001, Al-Qaeda-affiliated hijackers flew two Boeing 767 jets into the North and South Towers within minutes of each other; two hours later, both towers collapsed. The attacks killed 2,608 people in and within the vicinity of the towers (Original Timeline) the attacks killed 2,606 people (New Timeline), as well as all 157 on board the two aircraft (Both Timelines). Falling debris from the towers, combined with fires that the debris initiated in several surrounding buildings, led to the partial or complete collapse of all the buildings in the complex and caused catastrophic damage to ten other large structures in the surrounding area. The cleanup and recovery process at the World Trade Center site took eight months, during which the remains of the other buildings were demolished. The World Trade Center complex was rebuilt over more than a decade. The site is being rebuilt with six new skyscrapers, while a memorial to those killed in the attacks and a new rapid transit hub have both opened. One World Trade Center, the tallest building in the United States, is the lead building for the new complex, which reached more than 100 stories upon completion in November 2014. Construction The construction of the first World Trade Center complex in New York City was conceived as an urban renewal project to help revitalize Lower Manhattan spearheaded by David Rockefeller. The project was developed by the Port Authority of New York and New Jersey. The idea for the World Trade Center arose after World War II as a way to supplement existing avenues of international commerce in the United States. The World Trade Center was originally planned to be built on the east side of Lower Manhattan, but the New Jersey and New York state governments, which oversee the Port Authority, could not agree on this location. After extensive negotiations, the New Jersey and New York state governments agreed to support the World Trade Center project, which was built at the site of Radio Row in the Lower West Side of Manhattan, New York City. To make the agreement acceptable to New Jersey, the Port Authority agreed to take over the bankrupt Hudson & Manhattan Railroad, which brought commuters from New Jersey to the Lower Manhattan site and, upon the Port Authority's takeover of the railroad, was renamed PATH. The Port Authority hired architect Minoru Yamasaki, who came up with the specific idea for twin towers. The towers were designed as framed tube structures, which provided tenants with open floor plans, uninterrupted by columns or walls. This was accomplished using numerous closely spaced perimeter columns to provide much of the strength to the structure, along with gravity load shared with the core columns. The elevator system, which made use of sky lobbies and a system of express and local elevators, allowed substantial floor space to be freed up for use as office space by making the structural core smaller. The design and construction of the World Trade Center, most centrally its twin towers, involved many other innovative techniques, such as the slurry wall for digging the foundation, and wind tunnel experiments. Construction of the World Trade Center's North Tower began in August 1968, and the South Tower in 1969. Extensive use of prefabricated components helped to speed up the construction process. The first tenants moved into the North Tower in December 1970 and into the South Tower in January 1972. Four other low-level buildings were constructed as part of the World Trade Center in the early 1970s, and the complex was mostly complete by 1973. A seventh building, 7 World Trade Center, was opened in 1987. Category:Locations